Inkjet print head units have a droplet forming unit, for example based on a piezo-electric actuator generating a pressure wave in a recording liquid such as an ink, the generated pressure wave resulting in a droplet of recording liquid being expelled through a nozzle, as is well known in the art. Further, for controlling the actuators, the print head unit may have an electronic print head controller. The print head controller may be configured to supply a suitable electric actuation signal to an actuator when a droplet needs to be expelled. Moreover, particular calibration data, specific for the droplet forming unit (hereinafter: the print head), may be stored in the print head controller such that the droplets that are expelled through the print head have optimal properties such as droplet size, shape, speed, and the like.
The presence of the print head controller increases the size of the print head unit considerably, while in a preferred embodiment, a number of print heads is arranged as close to each other as possible to minimize artefacts in the printed image. Therefore, it is known to position an electronic print head controller at a position away from the print head and even completely separate from the print head. This results in relatively long cabling with challenges in minimizing EMC-radiation effects. Further, with print head specific calibration data on the electronic print head controller, it may be preferred to have a dedicated print head controller per print head and therefore it may be desirable to have a direct mechanical coupling between the print head and the print head controller.
US2011/0074849A1 discloses a print head unit wherein a print head is mounted on a mounting member. Due to manufacturing tolerances, wirings to the print head may be rotated relative to the mounting member. In order to mount an electronic driver board on the mounting member, the mounting member provides for a rotatable holding element for holding the electronic driver board to compensate for the manufacturing tolerances. In an assembled state, the print head and the electronic driver board are fixed relative to each other.
To enable a dense arrangement of print heads, the electronic print head controller may be positioned adjacent to the print head. However, when mounted in a scanning (reciprocating) inkjet printing assembly, the weight of the print head controller may result in inertia forces acting on the print head. With the high demands on the accuracy of the droplet position and consequently on the pint head positioning, a complex and expensive mounting assembly may be required to ensure an accurate positioning and maintaining of such accurate print head position during printing for example as a result of the high accelerations during turning of direction of movement.